Punch press mechanism



April 27, 1937. v. A. BOKER PUNCH PRESS MECHANISM Filed May 18, 1935 2 Sheets-Sheet 1 w mi April 1937- v. A. BOKER I 2,078,706

PUNCH PRESS MECHANISM Filed May 18, 1935 2 Sheets-Sheet 2 15 Arronvno Patented Apr. 27, 1937 PATENT OFFICE PUNCH PBESS MEGHANISM- Vitus A. Baker, Minneapolis. Minn.

Application May 18, 1985, Serial No. 22,239'

My present invention relates to punch presses and, generally stated, consists of the novel devices, combinations of devices and arrangement of parts hereinafter described and defined in the claim.

Primarily, the invention is directed to the provision of an extremely simple and highly efflcient stop gauge for such presses. This device is operated automatically under the press action and serves to intercept and stop the movement of the stockstrip after each punching action, and to accurately gauge the step by step forward movement of the stock strip. The invention further provides certain other important features of construction relating to the manner of mounting and 5 supporting the die plate on its die set.-

In the accompa y s drawings, which illustrate a commercial form of the invention and wherein like characters indicate like parts throughout the several views:

Fig. 1 is a plan view showing the die plate, die set and stock strip;

Fig. 2 is a view partly in elevation but chiefly in section taken on the line 2-2 of Fig. 1, showing also the punch head and parts carried thereby;

Fig. 3 is a view partly in elevation and partly in transverse section taken on the line H of Fig.

2; and

Fig. 4 is a plan view showing the stamped blank.

The die set here illustrated is made up of a 0 shoe or main die support 4, and a supplemental die support 5. The shoe 4 is formed with a large vertical passage 6 and with an undercut longitudinal guide-way I through the intermediate portion of which the vertical passage 8 extends.

35 The supplemental support 5 is flanged to slide in the guide-way 'I and .is adapted to be securely anchored therein by the use of one or more set screws 8 that work with threaded engagement through one side of the shoe 4. Further features I 40 of construction of the support I will be later noted.

Detachably seated on the shoe 4 and accurately positioned thereon, preferably by dowel pins 8, is a die plate or die proper It. The pattern to be 5 cut from the stock strip in different instances will vary to suit the circumstances of the case, but in the illustration, the blank 11 to be cut from the stock strip is a sort of truncated crescent and hence the die plate is provided with a main pat- 50 tern-forming passage II, as best shown in Fig. 1.

Inasmuch as the die illustrated is of the progressive character, the die plate is provided with small perforations l2 located also as best shown in Fig. 1. To adapt the arrangement to the particular 55 form of pattern-punching die, above described.

the support I is formed with a passage It that corresponds to but is larger than the die passage ii, and it is further provided with punch discharge passages i4 that register with the punch passages l2. Also as shown, the member 5 is provided with'an upwardly projecting bearing pin it andwitha raisedportion i6 thatreinforce and assist in supporting that portion of the die plate Ill that is extended over the vertical passage 8.

The stock strip from which the blanks are to be punched, is indicated by the character 1!. This strip is adapted to be fed longitudinally through a guide passage formed by the die plate ill, a stripper-plate i1, and spacing strips l8, which parts i0, i1 and I8 are rigidly secured together by rivets It or the like. The stripper plate I! is formed with a passage 20 that registers with but is slightly larger than the pattern-forming die passage H, and it is also provided with perforations 2i that register with but are preferably slightly larger than the upper extremities of the passages i2, which latter and the registering passages l6 are preferably tapered so that they increase in diameter toward their lower ends.

In practice, the shoe 4 will be clamped or otherwise rigidly secured to the bed of the press. Also the die plate I 0 may be further secured to and clamped down upon the shoe by any suitable means such as clamps or screws, not shown,

The vertically reciprocating punch head 22 in the arrangement illustrated, carries a blanking or pattern-forming punch 23 and piercing punches 24. The pattem-forming punch 23 corresponds in horizontal cross-section to the punch passage I i of the die plate with which it is, of course, truly aligned. The piercing punches 24 are aligned with the corresponding passages 2i of the stripper plate i1 and passages l2 of the die plate III. In the construction illustrated, the punches 23 and 24 are directly mounted in a punch plate 22a which, in turn, is rigidly but detachably secured to the head 22 by screws or other means, not shown.

Under successive punching actions and progressive step by step movements of the stock strip 1!, there will be formed in the stock strip large passages Ha that correspond to the die passage H and also the stock strip will be perforated by the punches 24. The blanks cut from the stock at Ila are the parts used either in their stamped form or in modified form for the making of various useful devices. Here it will be noted that the punches 24 act to puncture the strip in advance of cutting of the blanks from the strip, but at such positions that the perforations will appear in the punched blanks;

this being in accordance with what is known as progressive punching.

we now come to the most important feature of the present invention, to'wit: the stop gauge. 5 This device involves a simple lever 25 which is adapted to be integrally stamped from sheet metal. This lever, at its inner end, is provided with a down-turned stop finger or projection 28 and at its intermediate portion relatively near to its stop finger .26 is slidably fulcrumed to the strlpperplate I'I, this. as shown, being accomplished'by a rounded portion 21 thatbears on the stripper plate and works under a yoke-like keeper strap 28 which, in the structure illusfinger 28 works isin the form of an oblong slot 'and" allows limited sliding action of lever 25.

'The outer end' of the slot definitely checks the travel of the finger 26 when in contact with the stock. The 'opposite'end fof "the 'slot serves to checkjthesliding action, of the lever 25, due, to the action of the obliquely disposed, compression spring; I Q

The tappet illustrated is formed by thehead ofia' screw bolt 30, the stemof which works through a. slot 3| of a bracket vHtowhich it is held by nuts". The bracket 32, in, turn, is rigidly secured to the head 22 by screws 34 that work through a slot in the base of said bracket and are screwed into the head 22. By means 'of the adjustment permitted by the; screw 30 and by the slots 3| and 35, the tappet head can be adjusted to any desired altitude, to any desired distance from the head, and may also be given lateral adjustments so that it will properly engage the free end of stop lever 25. The stop lever 25 is subject to a compression spring 36, see particularly Fig. 2, that is obliquely disposed between said lever and the stripper plate 11, so that it exerts not only an upward force on the projecting end of the lever (tending to move the finger 26 downward into operative position shown in Fig. 2), but also puts said lever under strain to move inward and position the stop finger 26 against the inner extremity of slots 29. This arrangement and operation is highly important as will appear from the description of the operation.

As a further feature of the invention, the die plate i0 is accurately held with the punches 23 and 24 properly aligned with the die pas- 6o sages, by means of dowel pins 31. These dowel pins 31 in the structure illustrated, are directly secured to the punch plate 22a and maintain engagement with closely engaging guide passages 38 formed through the die plate It, the spacing 65 strips [8 and the stripper plate H, see partic-' trated. is anchored to said stripper plate and.

to Fig.- 1A,)" m, r 3 i From theforegoing, it will be understood that The operation of the stop gauge is as follows:

when the stock is pushed forward against the depending portion of the stop gauge 2', the latter is moved over against the left end of the slot in the stripper plate and makes a positive stock stop which locates the stock in the required position for punching. As soon as the punch engages the stock, the tappet 80 will engage the left end of lever 25, causing the depending portion 28 to raiseout of contact with the stock and, by the action of the. spring", is caused to rest'upon the upper surface of that portion of the stock, which is left as scrap'between the punchings; so that when the punch'aaoends and the stock is fed forward, the depending portion 26 of the stop gauge will drop into the punched aperture of the stock and again stop the. stock for-the next operation of the descending punch.

This simple device has, in practice, been found highly efilcient both as-a means for intermitwith 'a minimum of space between the punched font openings of the strip-and resultlnltmlnimum waste of material.

Obviously, the tai misiziua' m' unnecessary the employrrien't n,- a skillful operator, rendersf'feve'ry punch movement of the head effective, and the punch-tube run at-a maximum of speed. vAll the operator has to do is to insert thefstock strip'in theguide passage and manually keep the stock strip under tension to move from the right toward-theleft in the structure illustratedls, capable of modification within the scope of theinvention herein disclosedand'claimed. i-.-;;.,.

The term ,punch press is herein used in a broad sense to include die mechanisms for punching holes in or making deformed depressions in metal strips, bars or sheets. a

Certain of the structure herein disclosed and which does not involve the stop gauge-will be made the subject matter of a divisional application. I

What I claim is:

In a punch press mechanism, the combination with a co-operating die and punch, said die having a stripper plate overlying the same and spaced therefrom to afiord a stock guideway, said stripper plate adjacent the punch passage thereof, having a short stop slot extended in the direction of the feed of. the stock, of a stop gauge in the form of an integral lever extended in the direction of the feed of .the stock, and mounted on said stripper plate for combined pivotal and endwise sliding movement in the direction, of the travel of the stock and provided with a depending,

stock-engagingstop finger working through said stop slot and limited in a sliding movement theresaid stripper plate by a yoke secured to the latter and freely embracing the former.

VITUS A. BOKER. 

